Chitosan Derivatives Research Articles

Green Film Forming Technology Based on Polydopamine Galvanized

At present, the mainstream passivation agent is chromate passivation agent, but it has the disadvantages of high toxicity and high price, so this project seeks to find a safer, cheap and green chromium-free passivation agent. Because dopamine and chitosan derivatives have certain corrosion inhibition properties on metals in acidic media, these polymer corrosion inhibitors can achieve high corrosion inhibition rates at high concentrations. Therefore, in this experiment, dopamine was added on the basis of sodium silicate, and the sample was passivated to explore the potential enhancement effect of dopamine on the passivated film performance. After the sample was treated, the impedance value could be fitted by electrochemical impedance spectroscopy and Zsimpwin software, and then the Tafel polarization curve was drawn. It was found that the addition of dopamine significantly improved the corrosion resistance of the passivated film. By promoting the positive shift of self-corrosion potential and greatly reducing the self-corrosion current density, the protective barrier effect of passivation film on metal matrix is effectively enhanced. Finally, the experiment successfully proved that the corrosion resistance of the passivation film after adding dopamine was better

Dual Antimicrobial Activity of HTCC and Its Nanoparticles: A Synergistic Approach for Antibacterial and Antiviral Applications Through Combined In Silico and In Vitro Studies

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC), a quaternized chitosan derivative, has been shown to exhibit a broad spectrum of antimicrobial activity, especially against bacteria and enveloped viruses. Despite this, molecular docking studies showing its atomic-level mechanisms against these microorganisms are scarce. Here, for the first time, we employed molecular docking analyses to investigate the potential antibacterial activity of HTCC against Staphylococcus aureus and its antiviral activity against human immunodeficiency virus 1 (HIV-1). According to the findings, HTCC exhibited promising antibacterial activity with high binding affinities; however, it had limited antiviral activity. To validate these theoretical outcomes, experimental studies were conducted. Different derivatives of HTCC were synthesized and characterized using NMR, XRD, FTIR, and DLS. The in vitro assays validated the potent antibacterial efficacy of HTCC against S. aureus, whereas the antiviral studies did not show good antiviral activity. However, our research also revealed a promising avenue for further exploration of the antimicrobial activity of HTCC nanoparticles (NPs), since, thus far, no studies have been conducted to show the antiviral activity of HTCC NPs against HIV-1. The nanosized HTCC exhibited superior antiviral performance compared to the parent polymers, with complete (100%) inhibition of HIV-1 viral activity at the highest tested concentration (0.33 mg/mL).

Aminosilane@mesoporoussilica/chitosan∗salicylaldehyde nanohybrid: synthesis, characterization and applications

“Hydrogen-borrowing” mechanism has enables the production of biologically active molecules with minimal waste, high efficiency and mild reaction conditions. However, majority of research on the above mechanism has been focused on small molecule transformations. Hence, using Fe-tetraphenylcyclopentadienone tricarbonyl complex as a catalyst for “hydrogen-borrowing” mechanism between amines and alcohols, a novel pH-responsive inorganic-organic hybrid nanocarrier based on mesoporous silica-chitosan (MSN@CONH2/CS∗SCA) was developed to overcome these limitations. The nanocarrier was fabricated through C-N bond formation between 1-[3-trimethoxysiliylpropyl] urea functionalized mesoporous silica and salicylaldehyde modified chitosan derivative for antibacterial, antioxidant and drug delivery application. The chemical composition of synthesized nanocarrier was characterized by FTIR, 1H NMR and XRD techniques while the thermal stability examined through TGA. The surface morphology and porosity were evaluated using BET, SEM, and TEM whereas elemental composition, particle size and surface charge were determined by EDX with mapping, PSA and Zeta-potential method respectively. The nanohybrid was loaded with quercetin and curcumin drug, with 82.68 % and 83.24 % encapsulation efficiency respectively. The controlled drug release for quercetin was observed with 76 % (pH-5.0) and 20 % (pH-7.4), while for curcumin it observed 70.36 % (pH-5.0) and 19.16 % (pH-7.4) in 72 h. The antibacterial performance of nanocarrier shows better zone of inhibition for E. coli [2.9 ± 0.2 cm(3)] as compared to B. subtilis [1.6 ± 0.3 cm(3)]. The antioxidant ability of nano-hybrid to scavenge DPPH and ABTS radicals were 53.18 % and 55.21 %, respectively. Thereafter, MTT cytotoxicity assay of nanohybrid on peripheral blood mononuclear cells) exhibited promising results for biomedical applications.

Synthesis, Identification, and anti-cancer Evaluation of Some heterocyclic Chitosan-Thiosemicarbazones compounds and their nickle (II) complexes

Chitosan (CS) a chemical substance taken from the shells of sea creatures that has various uses in industry, farming, and medicine, for example in medical dressings. Its derivatives significantly inhibit two types of cancer cells: Madin Darby Canine Kidney MDCK and MCF-7. These derivatives include thiosemicarbazones, heterocyclic moieties, and their metal (II) complexes. In this study, CS from crab shells is mixed with thiosemicarbazide (TSC). Then, imidazole-2-carboxaldehyde, oxazole-2-carboxaldehyde, and thiazole-2-carboxaldehyde reacted to make three different compounds from CS-TSC: [2a], [2b], and [2c]. The chemicals were mixed with nickel chloride to create nickel (II) chitosan 2-acetyl heterocyclic-2-thiosemicarbazone complexes. SEM and X-ray tests were performed on the powder, which showed that the nickel (II) chitosan thiosemicarbazone complexes had square and flat shapes. The synthesized compounds were tested to check their effectiveness in preventing MDCK and MCF-7. The study found that chitosan derivatives significantly inhibited MDCK and MCF-7.

Antifungal Activity of Vanillic Acid Grafted Chitosan Derivatives against Plant Pathogenic Fungi, Fusarium sp.

Antifungal Activity of Vanillic Acid Grafted Chitosan Derivatives against Plant Pathogenic Fungi, <i>Fusarium</i> sp.

Green chitosan extraction from Hermetia illucens waste breeding (prepupal cases): Characterization and bioadsorption activity

Heavy metal contamination has harmful consequences for the ecosystem. They are naturally non-biodegradable, and can cause severe ecotoxicity and numerous pathologies. Several bioadsorbents have been used for metal pollution control, and chitosan is one of the biomaterials that has proven to be an efficient adsorbent. The aim of the present work is to exploit the rearing waste of Hermetia illucens (prepupal cases), commonly known as the Black Soldier Fly (BSF), to produce chitin and its derivative chitosan by microwave-assisted process, and to study the interaction of this biopolymer with zinc and cadmium. All the samples obtained were characterized by several methods, including FTIR, XRD, TGA/DSC, 1H NMR, SEM, and viscosimetric studies. The chitosan obtained has interesting physicochemical properties with an acetylation degree (DA) equal to 2.3 %, Molecular weight (Mv) equal to 155 kDa, and a crystallinity index (ICr) around 51.26 %. Chitosan was also found to have an adsorption capacity of Cd and Zn around 141.05 mg·g−1 and 45 mg·g−1 respectively by absorption atomic spectroscopy (AAS). Results confirm the effectiveness of chitosan derived from BSF, obtained through an eco-friendly method, as a sustainable and efficient bioadsorbent for addressing heavy metal contamination.

Comparison of composite resins containing UV light-sensitive chitosan derivatives in stereolithography (SLA)-3D printers.

This study produced composite resins by combining acrylate, chitosan (CH), carboxymethyl chitosan (CMCH), hydroxypropyl chitosan (HPCH), and hydroxyethyl chitosan (HECH) to create materials suitable for use in 3D stereolithography (SLA) printers. Tripropylene glycol diacrylate (TPGDA), urethane acrylate (UA), and photoinitiator (Diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO)) were mixed. CH and its derivatives were added separately to the resin to obtain composite resins. The mechanical test results are clear; the optimum TPGDA: UA ratio was 1:1, the cure time was 60s, and the TPO ratio was 1%. The optimum viscosity of the resin is 340-350cP. Hydrophobic/hydrophilic properties of cured composite resins were examined. The addition of CH and its derivatives to the resin caused a decrease in compressive strength. Adding up to 2.5% CH, CMCH, and HECH to the resin significantly increased the tensile strength of the resin, giving it flexibility. The gel content of cured composite resins was between 97.72% and 96.11%. The cured composite resins demonstrated high chemical and solvent resistance to HCl, NaOH, and HF but exhibited limited resistance to toluene and chloroform. The accelerated UV aging test results show that adding CH derivatives to the resin makes the composite resin more prone to photooxidative aging.

Valorization of chitosan for sustainable soap production: Development, performance evaluation, and hygiene applications

This study investigates a new method for making soap by using chitosan (CH) obtained from discarded cephalopod waste. This strategy aims to tackle the environmental issues related to trash disposal. Low molecular weight chitosan (LMWCH) was developed by extracting chitin, converting into chitosan and subjecting it to gamma irradiation for reducing the molecular weight. The chitosan has a molecular weight of 982 Da, making it well-suited for being included in soap compositions and providing strong anti-microbial activity. The soap that was produced demonstrated desirable attributes, such as a moisture content of 17.13%, a pH level of 9, and a stable fatty acid content, indicating its potential for successful commercial use. The soap had significant antibacterial activity against common pathogens such as Methicillin Resistant Staphylococcus aureus (MRSA) and Candida albicans ( C.albicans). After 36 h, it produced zones of inhibition measuring 7.7 ± 1.05 mm and 8.4 ± 0.5 mm respectively. The research’s reliability is based on its meticulous experimental technique, which included comprehensive characterization of both the chitosan derivative and the final soap product. Moreover, conducting antimicrobial testing on widely recognized pathogens enhances the credibility of the soap’s possible practical uses in hygiene goods. Overall, this study underscores the feasibility of utilizing waste materials for sustainable soap production while offering potential antimicrobial benefits, thus contributing to both environmental conservation and public health.

Characterization of a Novel Acid-Stable Chitosanase from Lentinula edodes Suitable for Chitooligosaccharide Preparation

As high-value chitosan derivatives, chitooligosaccharides (COSs) with biodegradable, biocompatible, nontoxic, antimicrobial, and antioxidant activities have been widely applied in food-related fields. Chitosanases can hydrolyze chitosan to produce COSs. Herein, a chitosanase (LeCho1) from Lentinula edodes was successfully expressed in Escherichia coli and was then purified and characterized. LeCho1 had a low sequence identity with other chitosanases reported from the GH75 family. The recombinant protein showed a molecular mass of 27 kDa on SDS-PAGE. LeCho1 preferentially hydrolyzed chitosan with a high degree of deacetylation (DDA) and exhibited maximal activity (71.88 U/mg) towards 95% DDA chitosan at pH 3.0 and 50 °C. It possessed good stability at pH 2.0–6.0 and temperatures below 45 °C. Its hydrolytic activity was remarkably enhanced by the metal ion Mn2+ at 1 mM, while it was totally inhibited by 1 mM Fe3+ or 10 mM EDTA. Its Km and Vmax values were 0.04 μM and 76.81 μmol·min−1·mg−1, respectively, indicating good substrate affinity. LeCho1 degraded chitosan into COSs with degrees of polymerization (DPs) of 2–5, while it had no action on COSs with DPs of less than 5, revealing its endo-chitosanase activity. This study proved that chitosanase LeCho1 is a promising candidate in the industrial preparation of COSs due to its excellent properties.

Synthesis of N, N,O and O-carboxymethyl chitosan derivatives of controllable substitution degrees and their utilization as electrospun scaffolds for bone tissue engineering

Most chitosan (CS) carboxymethylation approaches are weighed down by insufficient description protocols regarding the reaction specificity and the degree of substitution (DS). Here, we provide three carboxymethylation protocols of enhanced specificity towards the amine (N-), amine/hydroxy (N,O-) and hydroxy (O-) groups of CS. The DS for all samples was found to be ∼70 %, as confirmed by NMR analysis. To illustrate the modified materials' potential in bone tissue regeneration, each derivative was blended with poly(vinyl alcohol) to prepare scaffolds via electrospinning. Both materials and electrospun membranes were characterized in terms of their physicochemical properties by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and water contact angle measurements. The electrospun membranes' swelling ratio, degradation, tensile strength, as well as morphology were also examined through scanning electron microscopy before and after heat treatment at 120 °C, which was used as a method of physical stabilization, leading to significantly enhanced degradation rate and mechanical strength. The three electrospun scaffold types were loaded with MC3T3-E1 pre-osteoblastic cells and their cell adhesion, viability and growth rate were assessed. Finally, osteogenic differentiation was examined by means of alkaline phosphatase activity measurement, calcium mineralization and formation of extracellular matrix markers, with all materials showing promising prospects.

New Family of Benzimidazole-Based Chitosan Derivatives against Penicillium expansum.

Penicillium expansum is the major fungus that causes blue mold and produces patulin, threatening human health. Due to health and environmental pollution concerns, chitosan (CS) has attracted more and more attention as a safer alternative to synthetic fungicides for the control of blue mold. In the present study, four different benzimidazole groups were introduced onto CS by the acylation reaction to obtain benzimidazole-based chitosan derivatives (R1b-R4b). After being well-characterized with Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis spectra), and nuclear magnetic resonance (NMR), their antifungal activities against P. expansum were screened. Results showed that the inhibitory effects of chitosan derivatives against the pathogen were significantly correlated with chitosan derivatives' concentration and their structures. R4b was shown as optimum with good solubility and antifungal activity with a minimum inhibitory concentration (MIC) value of 0.5 mg/mL and a minimum fungicidal concentration (MFC) value of 2.0 mg/mL. The remarkable antifungal efficiency of R4b against P. expansum was further demonstrated in terms of spore germination, mycelial growth, patulin production, and the preliminary antifungal mechanism. R4b exhibited significant inhibition of patulin production, while its antifungal mechanism was revealed by destroying cell membrane integrity and inducing membrane depolarization. Furthermore, R4b treatment could significantly reduce the incidence of blue mold rot in apple fruit, and the MTT assay showed the nontoxicity of R4b against Raw 264.7, HBZY-1, and Caco-2 cells. Altogether, these results indicate that it is promising to be used as a fruit preservative in the future.

Isolation of a novel Bacillus strain with industrial potential of producing alkaline chitosanase.

A novel Bacillus strain, designated as HZ20-1, was discovered. This strain can produce naturally alkaline chitosanase without induction. Genomic analysis revealed that this chitosanase belongs to glycoside hydrolase family 8. When colloidal chitosan is used as a substrate, the maximum enzyme activity of 2.39±0.03U/mL is observed at a pH range of 8.5-9. This alkaline enzyme holds advantages over common acidic enzymes in various fields such as medicine, the environment, and daily chemical products, and thus has great market value. Moreover, as the chitosanase is a constitutive enzyme, there is no need for substrate induction. This can simplify fermentation equipment and reduce production cost. Additionally, in a preliminary study, we found that this strain can also degrade chitin and chitosan derivatives. After analysis, it was discovered that it has genes in glycoside hydrolase families 18 and 23. By controlling the enzymatic hydrolysis time, it is possible to produce products with different molecular weights, including N-acetylglucosamine, glucosamine, chito-oligosaccharides, and chitin oligosaccharides. Consequently, Bacillus sp. HZ20-1 is considered to have great potential for future industrial production of enzymes and oligosaccharides.

Chitosan-Based Composite Aerogel with a Rapid Tissue Hydration Layer-Triggered Response to Promote Hemostasis.

Aerogels exhibit poor adhesion to wet tissue surfaces, which is a significant factor that limits their hemostatic properties. In this work, we propose a new method for investigating aerogel hemostatic materials by introducing the concept of the 'rapid tissue hydration layer-triggered property' into the hemostatic material. A chitosan derivative (Csde) with a "swollen property" was prepared via an amide reaction, followed by the incorporation of the extracted bletilla striata complex (Bscai) into the chitosan derivative to fabricate the Bscai/Csde hemostatic material. The research results indicated that the Bscai/Csde hemostatic material exhibited a rapid tissue hydration layer-triggered response, outstanding hemostasis ability, as well as excellent hemocompatibility, antibacterial properties, and cytocompatibility. Additionally, the preparation method for the Bscai/Csde hemostatic material is straightforward, and the raw materials are readily available. Therefore, this study presents a novel method for developing a hemostatic material method, and the composite aerogel hemostatic material demonstrates considerable potential for future applications.

Interaction between reacetylated chitosan and albumin in alcalescent media

Interaction of chitosan and its derivatives with proteins of animal blood at blood pH relevant conditions is of a particular interest for construction of antimicrobial chitosan/protein-based drug delivery systems. In this work, the interaction of a series of N-reacetylated oligochitosans (RA-CHI) having Mw of 10–12 kDa and differing in the degree of acetylation (DA 19, 24, and 40 %) with bovine serum albumin (BSA) in alkalescent media is described in first. It is shown that RA-CHI forms soluble complexes with BSA in solutions with pH 7.4 and a low ionic strength. Light scattering study shows that soluble RA-CHI complexes have spherical form with the radius of about 100 nm. Circular dichroism, fluorescent spectroscopy, and micro-IR spectroscopy studies show that the secondary structure of BSA in soluble complexes remain intact. Isothermal titration calorimetry of RA-CHI with DA 24 % and BSA mixing in the buffers with different ionization heats reveals a significant contribution of electrostatic forces to the binding process and an additional ionization of chitosan due to the proton transfer from the buffer substance. An increase of ionic strength to the blood relevant value 0.15 M suppresses the binding. It is shown that application of RA-CHI with higher DA value leads to a decrease in the affinity of RA-CHI to BSA and an alteration of the interaction mechanism. The finding opens an opportunity to the application of N-reacetylated chitosan derivatives in the complex systems compatible with blood plasma proteins.

Carboxymethyl Chitosan-based Nanomaterials for Biomedical Applications: An Overview of Recent Advances and Prospects

Chitin is widely recognized as a highly abundant polymer found throughout the planet. This serves as a fundamental basis for the production of chitosan through deacetylation. Chitosan is non-toxic and biodegradable, making it highly suitable for applications as a biomaterial and in the development of drug delivery systems. However, the limited solubility of chitosan in neutral or alkaline environments has hindered its use in pharmacology and biology. Chitosan can undergo carboxymethylation, which enhances its water solubility while maintaining its biodegradability and compatibility with living organisms. Carboxymethyl chitosan (CMC) is a derivative of chitosan that is soluble in water and exhibits enhanced biological and physicochemical properties compared to chitosan. The CMC, or modified CMC, is a highly versatile agent with many applications. It has shown great promise in drug delivery, wound healing, bioimaging, biosensors, tissue engineering, and gene therapy. This study investigates the properties and potential applications of materials derived from carboxymethyl chitosan. These materials have attracted significant interest due to their versatility and fascinating possibilities in biomedical nanodevices and controlledrelease medication formulations.

Methylene blue sorption performance of lignocellulosic peach kernel shells modified with cellulose derivative chitosan as a new bioadsorbent

In this study, adsorption isotherms (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) and thermodynamic properties of cationic methylene blue (MB) dye adsorption onto chitosan-coated peach kernel shell waste (CTS-PKSh) from wastewater were investigated. CTS was cross-linked with citric acid (CA) and glutaraldehyde (GA). The adsorbents were characterized by FE-SEM/EDS, FTIR, and particle size distribution. MB adsorption behavior onto the biosorbents was investigated concerning parameters such as adsorbent dosage (0.8–8 g/L), time (0–540 min), pH (3−10), initial dye concentration (50–700 mg/L), and temperature (25–55 °C). The Langmiur qmax and experimentally qe MB adsorption capacities of the new adsorbents were found to be 227.27 and 201 mg/g for CA cross-linked CTS-PKSh (CA@CTS-PKSh) and 111.12 and 96.5 mg/g for GA cross-linked CTS-PKSh (GA@CTS-PKSh), respectively. The results of thermodynamic analysis showed that adsorption was feasible, exothermic, and spontaneous. According to adsorption and recyclability results, CA@CTS-PKSh was more effective for MB removal at a 2 g/L adsorbent dose for an initial dye concentration of 100 mg/L, 25 ± 1 °C, contact time 60 min, and pH 7.

Chitosan grafted with gallic acid and cerium dioxide hybrid nanocomposites as environmentally friendly corrosion inhibitors for mild steel: An experimental and computational study

Chitosan grafted with gallic acid (CS-GA), along with CS-GA doped with CeO2 nanoparticles (CS-GA-CeO2) were synthesized as novel environmentally friendly mild steel corrosion inhibitors. The formation of these derivatives was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), hydrogen nuclear magnetic resonance spectroscopy (1H NMR), and thermal analysis (TGA). Based on potentiodynamic polarization curves (PDP) measurements, the inhibitors acted primarily as hybrid inhibitors, while following the Langmuir adsorption theory model. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy(XPS) and 3D surface profiles, confirmed that CS-GA-CeO2 adsorbed on the mild steel forming a protective layer thus preventing the invasion of corrosive media. The corrosion protection mechanism of chitosan derivatives was investigated by molecular dynamics simulations. Electrochemical measurements were used to investigate the corrosion inhibition by CS-GA and CS-GA-CeO2 on mild steel in a 3.5 % NaCl solution. At room temperature, the highest inhibition efficiency (93.58 %) was achieved at 200 ppm CS-GA-CeO2. Modified chitosan nanocomposites were confirmed as promising corrosion inhibitors.

Self-assembling chitosan based injectable and expandable sponge with antimicrobial property for hemostasis and wound healing

Chitosan and chitosan derivative are widely used in hemostasis, antibiosis and wound repair for its good biocompatibility and unique effect. However, the preparation of chitosan based hemostatic materials or wound dressings generally involves chemical crosslinking agent introduction, acid residue or complicated preparation process, which limits its clinical application. In this study, an injectable and expandable chitosan sponge was constructed by chitosan (CS) and quaternized chitosan (QCS) self-assembly without acid retention and chemical crosslinker introduction. In the neutral condition, the hydrogen bond of CS molecules can act as the driving force to form cross-linking network, and the QCS was introduced to regulate the hydrogen bond of CS to avoid the excessive aggregation. The porous QCS/CS sponge was obtained by freeze-drying of the self-assembly QCS/CS hydrogel. The sponge exhibited high expansibility, injectability and water/blood triggered shape memory property. Due to the introduction of QCS, the sponge showed good antibacterial properties, which can protect the wound from bacterial invasion. The convenient and green preparation method of injectable and expandable QCS/CS sponge is a potential method for the treatment of hemostasis and wound healing.

Synthesis and characterization of modified chitosan as a promising material for enterosorption of heavy metal ions

Currently, an important ecological problem is environmental pollution and its negative impact on living organisms, the consequences of which are deterioration in general health and the manifestation of various diseases, poisoning, endo- and exotoxicosis. Enterosorption method was proposed as a promising method for removing toxic substances from the living organisms using enterosorbents which can absorb various toxic substances of endogenous and exogenous nature in the lumen of the gastrointestinal tract. It has been proposed to use polymer-containing enterosorbents for eliminating of heavy metals from the organism. The purpose of this research was to synthesize a quaternized derivative of chitosan, specifically N-(2-hydroxybenzyl)-N-ethyl-N-methyl chitosan chloride (Q-CHS). The synthesis of Q-CHS involved the formation of a Schiff base, followed by the quaternization of the amino group of chitosan (CHS). The structures of both pure CHS and quaternized CHS were studied using various physico-chemical methods, including FTIR, NMR, XRD, SEM, DSC and TGA analyses in order to determine the structure and confirm the formation of the final product.

PH-Sensitive Fluorescent Probe in Nanogel Particles as Theragnostic Agent for Imaging and Elimination of Latent Bacterial Cells Residing Inside Macrophages.

Rhodamine 6G (R6G) and 4-nitro-2,1,3-benzoxadiazole (NBD) linked through a spacer molecule spermidine (spd), R6G-spd-NBD, produces a fluorescent probe with pH-sensitive FRET (Förster (fluorescence) resonance energy transfer) effect that can be useful in a variety of diagnostic applications. Specifically, cancer cells can be spotted due to a local decrease in pH (Warburg effect). In this research, we applied this approach to intracellular infectious diseases-namely, leishmaniasis, brucellosis, and tuberculosis, difficult to treat because of their localization inside macrophages. R6G-spd-NBD offers an opportunity to detect such bacteria and potentially deliver therapeutic targets to treat them. The nanogel formulation of the R6G-spd-NBD probe (nanoparticles based on chitosan or heparin grafted with lipoic acid residues, Chit-LA and Hep-LA) was obtained to improve the pH sensitivity in the desired pH range (5.5-7.5), providing selective visualization and targeting of bacterial cells, thereby enhancing the capabilities of CLSM (confocal laser scanning microscopy) imaging. According to AFM (atomic force microscopy) data, nanogel particles containing R6G-spd-NBD of compact structure and spherical shape are formed, with a diameter of 70-100 nm. The nanogel formulation of the R6G-spd-NBD further improves absorption and penetration into bacteria, including those located inside macrophages. Due to the negative charge of the bacteria surface, the absorption of positively charged R6G-spd-NBD, and even more so in the chitosan derivatives' nanogel particles, is pronounced. Additionally, with a pH-sensitive R6G-spd-NBD fluorescent probe, the macrophages' lysosomes can be easily distinguished due to their acidic pH environment. CLSM was used to visualize samples of macrophage cells containing absorbed bacteria. The created nanoparticles showed a significant selectivity to model E. coli vs. Lactobacillus bacterial cells, and the R6G-spd-NBD agent, being a mild bactericide, cleared over 50% E.coli in conditions where Lactobacillus remained almost unaffected. Taken together, our data indicate that R6G-spd-NBD, as well as similar compounds, can have value not only for diagnostic, but also for theranostic applications.